You Docs: Exercise is as good for the brain as it is for the body

Do you think you're getting that shiny new exercise bike you asked for? Or maybe it's "Just Dance 3," the super-fun new Wii workout, that you want? And did you just blast in from your daily walk, rosy-cheeked and ready to rip?

Awesome.

That's your memory applauding, not just us. That walk gave you a jolt of something called (sorry about this) brain-derived neurotrophic factor, better known as BDNF. (Think of it as Miracle-Gro for your brain!)

We and many others have long been convinced that exercise improves mental as well as physical fitness, and we know it increases BDNF, so it seemed likely that the two were connected. But the specific links were elusive. Now four new, very different studies have concluded that exercise-boosted BDNF sharpens your memory, recall and ability to do tricky tasks (negotiate airport parking; manage your boss, who seems to be short on BDNF; or land eight tiny reindeer on a roof).

The studies were done on Irish college students, U.S. airplane pilots, elderly rats in Brazil and younger ones in California. The super-short punchline: Immediately after physical activity (riding a bike, running a maze), brain levels of BDNF shoot up and so does mental agility. Work out regularly, and they stay up. If you have a genetic tendency to lose BDNF with age (some people do), exercise may be even more important for memory and task skills.

So if you-know-who doesn't come through with that bike or Wii workout, buy 'em for yourself. Just say that your brain made you do it.

The YOU Docs, Mehmet Oz, host of "The Dr. Oz Show" and Mike Roizen of Cleveland Clinic, are authors of "YOU: Losing Weight." For more information go to www.RealAge.com